OBJECTIVE: To assess the prevalence and related factors of root caries in Turkish 35-44 and 65-74 year-olds.BASIC RESEARCH DESIGN: In this cross-sectional study, using a proportional stratified cluster sampling, 1,631 subjects aged 35-44 years and 1,545 aged 65-74 years were examined. Data were collected via a structured, pre-tested face-to-face administered questionnaire and oral examination following WHO 1997 guidance. Statistical significance was evaluated with chi2 test and binary logistic regression analyses to determine the significance of explanatory variables.RESULTS: The prevalence of root caries was 20.1% in dentate 35-44 year-olds, 28.4% in 65-74 year-olds. Mean decayed root increased significantly with the increasing number of retained natural teeth (p = 0.010 for 35-44 and p < 0.001 for 65-74 year-olds). First molars were the most affected by root caries in both age groups. For adults, being male (OR = 1.37), rural residence (OR =1.50), being unschooled (OR = 3.07), no tooth brushing (OR = 1.83) and never visiting dentist (OR = 2.03) were the predictors of the presence of root caries. For elderly, rural residence (OR = 1.54), no tooth brushing (OR = 1.89), and never visiting dentist (OR = 2.38) were the determinants of root caries.CONCLUSION: There is a need for the increased implementation of oral health measures with increasing age in Turkey.